Randall wrote:It's unlikely that any one piece of satellite debris will hit someone. But there are several hundred million passenger cars in the United States alone. If all of them were suddenly shot into orbit and allowed to reenter, it's likely that somewhere between a few hundred and a few thousand people would be injured or killed by falling engine blocks, transmissions, and half-melted axles.On the other hand, about thirty thousand Americans are killed each year in motor vehicle accidents. So while launching all our cars into space—and letting them fall back down and hit us—might sound like a bad idea ...... it's arguably a lot safer than continuing to drive them.

That only works if you're nice enough to let people leave their cars before you teleport their cars into space.

You can get things happening like this. (from "The heavily loaded skip is raised into place as the pin is fixed in place")

(brief google doesn't find a convenient short clip of the video, at least available in my country, but basically one of the many cables catches on something, the machine tears itself apart and hurls the mini a grand total of 9m backwards)

Unstoppable force of nature. That means she/her/hers.Has committed an act of treason.

Echo244 wrote:(brief google doesn't find a convenient short clip of the video, at least available in my country, but basically one of the many cables catches on something, the machine tears itself apart and hurls the mini a grand total of 9m backwards)

... like when we leave a Teflon pot on the stove by accident. Actually, maybe we should look into that one...

Lots of parrot owners have lost their birds to this. I don't know how bad it is for humans but birds tend to die from it long before humans get distressed.

Just use ceramic-coated pots. They're not only nonstick but they're crazy scratch-resistant too (you can still chip the coating if you apply too much localized pressure, but random contact with metal implements doesn't do any damage).

You can get things happening like this. (from "The heavily loaded skip is raised into place as the pin is fixed in place")

(brief google doesn't find a convenient short clip of the video, at least available in my country, but basically one of the many cables catches on something, the machine tears itself apart and hurls the mini a grand total of 9m backwards)

Trebuchet design and construction seems to be one of those things which look easy, but isn't. In particular, the exact shape of the hook whichreleases one end of the sling as the shaft approached vertical is a very sensitive area.

One of the last military uses of the trebuchet was in Cortez's Seige of Tenochtitlán (Mexico City) in 1521. They were running short on gunpowder for their cannon, but they had an early military nerd among them:

"...There was a soldier in Cortez's camp who said he'd been in Italy, in the Great Captain's company, and was in the affair at Garellano and other great battles. He talked a good deal of war-engines, and said he could make a catapult in Tlatelolco which, if they were to bombard the quarter of the city into which Guatemoc had retreated, would make them sue for peace in two days.

He talked so much about it, for this man was a great talker, that Cortez promptly set to work on the catapult. They brought lime and stone and wood, as the soldier requested, and carpenters and nails and all that was needed for its construction. They made two slings of strong rope and cords, and brought up great stones bigger than demijohn jars, and when the catapult was made and rigged as he desired, the soldier said that it was ready to be discharged.

So they placed a suitable stone in the sling, but all it did was to rise to the height of the catapult and fall back to its original place.

Cortez was very annoyed with the deviser of the catapult and with himself for having believed him. He said that the man had proved that nothing was more prejudical to war than talk, and that the whole matter had been one of talk for talking's sake; and he at once ordered the catapult to be taken to pieces..." - from Bernal Diaz's "History of the Conquest of New Spain" (Diaz was part of the expedition, writing this 50 years later)

In the better versions of this story, the stone, landing 'in its orginal place' smashes the trebuchet on its first shot.

Okay, this is terribly off topic, but hi! I'm new! However, forum navigation is not my strong suit. Is there an 'introductions' thread or a place for new people? I'll keep looking until someone gets back to me.Thanks!

eviloatmeal wrote:What if we built a big tube - sort of like a hydraulic lift - and then lifted the Jetta up out of the atmosphere by pumping CO2 in underneath it?

That way we kill two birds with one bush: Shoot the cause into space, and flush the symptom out along with it.

(Reasonably-long-time-reader, first-time-poster; making my first mark on a point I've been considering for a couple of days already, hence the forthcoming length...)

This would help flush some CO2 from the overpressure1 , just so long as nobody expects a pipe to space to fully evacuate itself to vacuum, once its job as a spud-gun/launcher has completed.

Barring a bit of oscilation-induced overspill and after the effects of temperature on localised gas-volume have equalised or matched the atmosphere, you'll probably end up with a tube into space filled with carbon dioxide at roughly atmospheric pressure (perhaps 1.5x?) at ground level and petering out to be exactly-as-thin-as-space-is-at-the-top at the top. Then you've got a pipe full of carbon-dioxide that you don't want to let uncontrollably empty back out, at all. (Although it appears the infamous Lake Nyos episode released several million times more gas than would be potentially contained within this pipe, so it might not be catastrophic on that level.)

You could keep pumping waste gas into the bottom at greater than atmospheric pressure and it would move up and out the open end. But I'm wondering if, as a comparitively 'heavy' gas, it may well just mostly 'pour' back down the outside the pipe if not also given supplemental heat at the top end to give it some form of brownian escape velocity to rival the lighter elements that are being slowly stripped away by the various methods of atmospheric loss we already have. Certainly you'd be putting a large amount of energy into the 'CO2 waterfall', so I hope you've at least used carbon-neutral methods to power the CO2 extractor/pressuriser, if not in the construction of the space-pipe itself.

(If the pipe was made to reach beyond geostationary, rather than just 'into space', then you'd perhaps have something like the inverse of the siphon idea, from What-If 143. Enough pressure at the bottom2 to make the 'constrained atmosphere' within the tube be thick enough and extensive enough to stretch beyond the limits of any practical atmosphere, against the centripetal/whatever force. All gas exiting the tube top would spill 'outwards'. But then so would the car. But then that would cause no further impact on Earth's environment, by re-entering, except perhaps by a fluke of orbital mechanics or some other outside mechanism shoving it back again...)

If I had a spare envelope, I probably should have been making some calculations on the back of it. But it appears I didn't.

1 Needed to 'float' the projectile, although it wouldn't be buoyancy, and would depend on whether you're making it an air-tight plug or relying on the gas rushing past at great speed, probably somewhat greater than the terminal velocity of the projectile, however so affixed into the tube.

2 And a suitably pressure-resistant pipe. Is graphene laterally impermeably to CO2? Could a single-layer 'metre-or-so'-diameter graphene tube hold both itself up from the pressure (perhaps graphene-laying nanomachinery adding to its top-edge using, as feedstock, the carbon-rich gas being pumped past or at least into a temporary 'cap'?) and resist the outwards pressure eventually required? Or would it need to be multi-walled, to be sure...Hmmm....